HELP! We are preparing to install wall insulation (blown-in cellulose) into our uninsulated 1949 Ranch. The outside is "permastone" and the walls are plaster. In hanging our flat screen TV, we ended up with about 10 holes in the wall before we found a stud. Does anyone out there know what the stud spacing was in 1949? With plaster walls, I'd hate to drill 10 3" holes in the wall trying to locate the space between the studs.